Import and render raw volumetric data
Now, in the Blender 2.9x series, it is actually possible to import/export openVDB volume files in and out of the scene.
See this in the Blender manual for 2.91
In fact, there is even a mesh to volume modifier for meshes in the scene, which is extremely helpful for rendering complex volumes in EEVEE without having to do serious procedural node working.